Flame cutting torches



April 17, 1962 Filed NOV. 16, 1960 F. J. STONEBERG ET AL FLAME CUTTINGTORCHES 2 Sheets-Sheet l F. J. STONEBERG ET AL April 17, 1962 FLAMECUTTING TORCHES 2 Sheets-Sheet 2 Filed Nov. 16, 1960 INVENIOR.

United States Patent 3,029,864 FLAME CUTTING TORCHES Fred J. Stoneberg,646 N. Laramie Ave, and Raymond Dorweiler, 2714 W. Bilden Ave., both ofChicago, Ill. Filed Nov. 16, 1960, Ser. No. 69,708 3 Claims. (Cl.158-27.4)

Our invention relates to improvements in torches useful in the flamecutting of metals. In particular, the invention provides an improvedflame cutting torch and a novel pressure regulation and gas flow controlassembly for selectively controlling the pressure and flow of gasessupplied to torches used in the machine of automatic cutting of metals.

Conventionally torches for flame cutting of metal are designed toutilize fuel gas,-e.g. acetylene, propane or other combustible gas, andoxygen from tanks or cylinders at relatively high pressure for bothcombustion and for cutting. The higher the pressure, the greater is theeiliciency although also the consumption of gases is higher. In ordinarytorches, the oxygen and fuel gas are supplied at a constant tankpressure preset by a pressure type flow regulator associated with thesupply tank. The pressure may be further adjusted by means of handvalves associated with the oxygen and fuel gas inlet pipes.

Usually, the pressure is of the order of 100 to 125 p.s.i.g. for theoxygen supply and 20 to 50 p.s.i.g. for the fuel supply, designed toprovide, or approximate, a neutral flame for maximum heat during thepreheating cycle. Additional oxygen for the cutting cycle is also madeavailable at the regulated oxygen supply pressure through a separateline. Conventionally, the pressures are preset, and the mixture isadjusted by manual set valves. Usually lever means for switching fromthe preheat cycle to the cutting cycle is provided.

Operation with the combustion gases near or at the tank supply pressureis desirable for rapid and effective v preheating, but is unnecessaryfor cutting, once preheating has been accomplished. Obviously, suchoperation is highly wasteful of fuel and oxygen and in addition, at thehigh temperatures obtaining, results in excessive tip consumption.Although conventional torches are ordinarily equipped with hand valvesto permit adjustment of pressure (as well as mixture ratio) in the gaslines, the necessary adjustment is troublesome, time consuming and maybe difficult to attain with the accuracy necessary for effective flamecontrol. As a consequence, operators rarely attempt regulation byadjustment of valve settings to obtain optimum operation, in terms ofpressure or mixture, as they switch from the metal preheating to theflame cutting cycles.

In recognition of this problem, injection type torches have beendesigned in order to promote efficiency of fuel utilization, whichregulate flow of fuel gas by the volume and rate of flow of oxygen. Thedifficulty with such injection type torches, however, is that during thepreheating cycle, the pressure (or flow) of combustion oxygen and fuelgas are so low that protracted heating times are required as apreliminary to cutting. For example, a period of A2 to 1 /2 minutes iscustomary in comparison to 4 to seconds using flow at normal regulatedtank pressures. The protracted preheating time over the usual workperiod results in excessive consumption of fuel gas, despite reducedcombustion oxygen pressure. Also in significant additional cost, becauseof increased tip consumption, slower production rates, designcomplexity, and the like.

It is an object of the invention to provide an improved frame cuttingtorch, equipped with means for selectively regulating the pressure, flowand operation of both fuel gas and oxygen during the preheating andcutting cycles in order to reduce consumption of fuel gas and oxygenwhich is susceptible of quick automatic control. It is a further objectto provide a torch and burner, including an improved flow regulatorvalve assembly, which permits utilization of relatively inexpensive andreadily available fuels such as propane and methane or other gases ofpetroleum origin. Another object is to reduce preheating time byimprovement in control of the pressure and flow of combustion gases in amanner permitting speedup of production rates and, concomitantly, tipsavings resulting from cool operating tips.

It is a further object of the invention to provide a pressure controlassembly which is specially adapted for embodiment in machine torchesused in assembly line or automatic operation.

According to the invention, a pressure control assembly is provided forcontrolling the flow of gas through the delivery tubes for combustionand cutting gases in flame cutting torches. prises a first control headfor the combustion oxygen and fuel gas, a second control head forcutting oxygen, and lever means positioned between the two control headsin a manner permitting rapid switching from high to low pressure flow ofthe combustion gases while simultaneously opening the flow of cuttingoxygen.

The first control head comprises a fuel gas inlet channel with a conduitfrom the channel to the fuel gas delivery tube and adjustable valvemeans associated therewith for controlling the flow of fuel gas. Abypass conduit is provided from the inlet channel to a valve chambercontaining a quick acting valve such as a springloaded, plunger typevalve. chamber to the fuel gas delivery tube contains an elongated valvestem which is adapted to actuate the valve when pressure is applied tothe tip of the stem. Also, in the first flow control head a conduit isprovided from an oxygen inlet channel to the combustion oxygen deliverytube. Adjustable valve means is provided for controlling the flow ofoxygen through the conduit. A second conduit from the oxygen inletchannel is provided to the combustion oxygen delivery tube. Quick-actingvalve means comprising a spring-loaded valve member and a reciprocablestem adapted to open and close the valve member is provided forcontrolling the flow of combustion oxygen through the second conduit ina manner similar to that of fuel gas.

The second control head comprises a conduit from the oxygen inletchannel to the cutting oxygen delivery tube. Quick-acting valve meanscomprising a spring-loaded valve member and reciprocable valve stemadapted to open and close such member provides control of cuttingoxygen.

The lever means is located between the two flow control heads andessentially comprises a rotatably mounted cam adapted by means of a lobeto apply pressure alternately against the valve stem of the secondcontrol stem thereby switching from high to low pressure flow of thecombustion gases .while opening flow of cutting gas.

The invention will be further described by reference to the accompanyingdrawings, illustrating in particular embodiment of the invention,wherein:

FIGURE 1 is an elevational view showing a torch utilizing the inventionin profile and in partial longitudinal section.

FIGURE 2 is a plan view partially sectionalized and cut away of thetorch of FIGURE 1.

FIGURE 3 is an end view of the torch.

FIGURE 4 is partial section through the portion of the torch shown inFIGURE 3.

FIGURE 5 is a detail of the control head of FIGURE 2 in longitudinalsection.

The assembly essentially com- A conduit from the valve FIGURE 6 is aperspective section, partialiy broken away, of the torch.

In FIGURE 1, the essential parts of the torch may be seen: thecombustion gas pressure control head 10, the cutting oxygen control head11, the lever control systern 12 situated between the two pressurecontrol heads, the mixing head assembly 13, the burner tip 14, and theindividual gas delivery tubes, respectively, the cutting oxygen tube 15,the combustion oxygen tube 16 and the fuel gas tube 17.

Control head is best seen in FIGURE 5. Fuel gas is charged to the torchin the usual manner by means of threaded connection 20. Fuel gas inletchannel 21 is machined or bored in the head and provides a passagewayfor fiow of fuel gas to tube 17 via conduit 22. An adjustable valve, forexample, a conventional threaded needle valve 23 controls fiow frominlet channel 21 and conduit 22 to delivery tube 17. A second conduit 24connects the inlet channel 21 with a valve chamber 25 which contains aspring-loaded plunger valve 26. A cylindrical conduit 27 provides apassageway from valve chamber 25, via a connecting conduit 27a, to thecombustion gas tube 17. An elongated valve stem 28, is reciprocnblymounted in conduit 27. The tip of valve stem or rod 28 projects asindicated at 29 beyond the packing gland 30 and nut 31.

Oxygen is charged to the pressure control assembly through threadconnection 32 which opens into inlet channel 33. Conduit 34 provides aconnection from inlet channel 33 to combustion oxygen delivery tube 16.Threaded needle valve 35 is provided for manual adjustment of flowthrough the system. From the inlet channel 33, conduits 36 and 37control such flow. A spring-loaded valve member 40 is contained in valvechamber 38, which in turn communicates by means for an elongatedcylindrical conduit 41 and associated connection passage 41a withcombustion oxygen delivery tube 16. Reciprocable in conduit 41 iselongated valve stem 42 of valve member 40. The tip 43 of the rod typeplunger valve stem 42 projects beyond the packing gland 44 and nut 45.

Flow of oxygen from the inlet channel to the cutting oxygen system isprovided by a conduit 45a which connects with section 15a of cuttingoxygen delivery tube 15 and terminates in the second flow control head11. Communication from section 15a is via conduits, 46 and 47, thelatter of which opens into valve chamber 48. Spring loaded valve member49 is operative in chamber 48 and is actuated by rod member 50 which isreciprocable in conduit 47. Tip 51 of the rod type valve stem 50projects beyond the packing gland 52 and associated nut 53. Conduit 54provides a connection between valve chamber 48 and cutting oxygendelivery tube 15.

The openings from oxygen inlet channel 33 to conduits 34, 36 and 45a maybe seen in FIG. 4 where they are designated respectively as 33a, 33b and330.

The lever control system, operative between the two flow control heads10 and 11, comprises rotatably mounted cam which is designed preferablyto have two lobes 61 and 62. As shown, the lobes are set approximatelyapart. Cam 60 is rotated by action of lever arm 63 in a manner which mayalternately apply actuating pressure, upon valve stem tips 29 and 43,which advantageously are paired by means of bar 64, and on valve stemtip 51. Because of the resulting reversed reciprocation of the valvestems, valves 26 and 40 are opened while valve 49 closes, and viceversa.

It will thus be apparent that in operation, the torch can be lighted upwith lever arm 63 and cam 60 in the neutral, or central position. Insuch position, the three spring-loaded plunger valves 26, 40, and 49 areclosed. Hence, flow of combustion oxygen and fuel gas flow through thepassageways and restrictive orifices (to obtain design pressure drops)under control of needle valves 23 and 35 as normally preset. Forpreheat, lever arm 63 is moved in the direction indicated by arrow 65,thereby forcing lobe 61 of cam 66 against yoke bar 64 and valve stemtips 29 and 43. As a consequence, valves 26 and 40 are opened andadditional combustion oxygen and fuel gas flow individually throughvalve chambers 38 and 25 respectively, to provide high pressurepreheating combustion conditions at the tip. The result is rapidpreheating, with significant gas savings. Upon the completion ofpreheating, the position of lever arm 63 is reversed to that shown inFIGURE 6, which has the effect of forcing cam lobe 62 against valve stemtip 51, while at the same time releasing valve stem tips 29 and 43. Theeffect is to return the flow of combustion gases to a low pressurecondition while simultaneously opening the flow of cutting oxygen athigh pressure. The leverage control system, located between the twopressure control heads, provides a remarkably simple system forselective control of the pressure and flow of combustion cutting gasesin flame cutting torches. Gas and tip economies are effected, andgreater flexibility in utilization of lower B.t.u. gases is provided.Because of the simplicity of mechanical design the assembly can bedesigned as a unit adapted for use with a variety of different torches.The simplicity and ease in design and operation of the lever controlsystem also makes the assembly particularly suited for use with machineoperated torches, particularly those of the vertical type, which areused in multiple sets in the automated flame cutting of metal.

We claim:

1. A pressure control assembly for controlling flow of gases throughdelivery tubes for combustion and cutting gases in a flame cutting torchwhich comprises a first control head containing a fuel gas inletchannel, a conduit from said channel to a fuel gas delivery tube,adjustable valve means associated therewith for controlling flow of thegas therethrough, a conduit from said fuel gas inlet channel to the fuelgas delivery tube, quick-acting valve means comprising a spring-loadedvalve member and a reciprocable stem adapted to open and close saidvalve means associated with said conduit for controlling flow of fuelgas therethrough, an oxygen inlet channel, a conduit from said oxygeninlet channel to a combustion oxygen delivery tube, adjustable valvemeans associated therewith for controlling fiow of the oxygen gastherethrough, a second conduit from said oxygen inlet channel to thecombustion oxygen delivery tube, quick-acting valve means comprising aspring-loaded valve member and a reciprocable stem adapted to open andclose said valve mean associated with said conduit for controlling flowof combustion oxygen therethrough, a second control head for cuttingoxygen comprising a conduit from the oxygen inlet channel to a cuttingoxygen delivery tube, a quickacting valve means comprising aspring-loaded valve member and a reciprocable stern adapted to open andclose said valve means associated with said conduit for controlling flowof cutting oxygen therethrough and lever means positioned between saidfirst and second flow control heads comprising a rotatably mounted camadapted via a lobe thereof to apply pressure alternately against thevalve stems of said first control head and against the valve stem ofsaid second control head thereby switching from high to low pressureflow of combustion gases while opening flow of cutting gas, and a leverrod adapted to actuate said cam.

2. In a flame cutting torch comprising a mixing head, burner tip, andseparate tubes for delivering fuel gas, combustion oxygen and cuttingoxygen to said mixing head and burner tip, a pressure control assemblyfor controlling fiow of gas and oxygen through said delivery tubes whichincludes a first control head for combustion gases including a fuel gasinlet channel, a conduit from said channel to said fuel gas deliverytube, adjustable valve means associated therewith for controlling fiowof the gas there through, a valve chamber, a conduit from said fuel gasinlet channel to said valve chamber a spring-loaded plunger-type valvein said valve chamber, an elongated cylindrical conduit and a connectingconduit means from said valve chamber to the fuel gas delivery tube, anelongated valve stem reciprocable in said cylindrical conduit, an oxygeninlet channel, a conduit from said oxygen inlet channel to thecombustion oxygen delivery tube, adjustable valve means associatedtherewith for controlling flow of the oxygen gas therethrough, a valvechamber, a spring-loaded plunger-type valve in said chamber, a secondconduit from said oxygen inlet to said valve chamber, an enlongatedcylindrical conduit and an associated connection passage communicatingsaid valve chamber with said combustion oxygen delivery tube, anelongated valve stem reciprocable in said elongated conduit, a secondcontrol head for cutting oxygen comprising a valve chamber, aspring-loaded plunger-type valve in said chamber, a conduit from theoxygen inlet channel to said valve chamber, an elongated cylindricalconduit and passage means communicating said valve chamber with thecutting oxygen tube, an elongated valve stem reciprocable in saidcylindrical conduit and lever means positioned between said first andsecond flow control heads comprising a rotatably mounted cam adapted viaa lobe thereof to apply pressure alternately against the valve stems ofsaid first control head and against the valve stem of said secondcontrol head thereby switching from high to low pressure flow ofcombustion gases while opening flow of cutting gas, and a lever rodadapted to actuate said cam.

3. In a flame cutting torch comprising a mixing head, burner tip, andseparate tubes for delivering fuel gas, combustion oxygen and cuttingoxygen to said mixing head and burner tip, a pressure control assemblyfor controlling flow of gas and oxygen through said delivery tubes whichincludes a first control head for combustion gases comprising a fuel gasinlet channel, a conduit from said channel to said fuel gas deliverytube, adjustable valve means associated therewith for controlling flowof the gas therethrough, a conduit from said fuel gas inlet channel tothe fuel gas delivery tube, quick-acting valve means comprising aspring-loaded valve member and a reciprocable stem adapted to open andclose said valve means associated with said conduit for controlling flowof fuel gas therethrough, an oxygen inlet channel, a conduit from saidoxygen inlet channel to the combustion oxygen delivery tube, adjustablevalve means associated therewith for controlling flow of the oxygen gastherethrough, a second conduit from said oxygen inlet channel to thecombustion oxygen delivery tube, quick-acting valve means comprising aspring-loaded valve member and a recipro-' cable stem adapted to openand close said valve means associated with said conduit for controllingflow of combustion gas therethrough, a second control head for cuttingoxygen comprising a conduit from the oxygen inlet channel to the cuttingoxygen delivery tube, quick-acting valve means comprising aspring-loaded valve member and a reciprocable stem adapted to open andclose said valve means associated with said conduit for controlling flowof cutting oxygen therethrough, and lever means positioned between saidfirst and second flow control heads comprising a rotatably mounted camadapted via a lobe thereof to apply pressure alternately against thevalve stems of said first control head and against the valve stem ofsaid second control head thereby switching from high to low pressureflow of combustion gases while opening flow of cutting gas, and a leverrod adapted to actuate said cam.

References Cited in the file of this patent UNITED STATES PATENTS2,372,305 Walker Mar. 27, 1945 2,482,843 Crouch Sept. 27, 1949 2,550,888Traughber May 1, 1951 FOREIGN PATENTS 857,258 France Apr. 15, 1940

1. A PRESSURE CONTROL ASSEMBLY FOR CONTROLLING FLOW OF GASES THROUGHDELIVERY TUBES FOR COMBUSTION AND CUTTING GASES IN A FLAME CUTTING TORCHWHICH COMPRISES A FIRST CONTROL HEAD CONTAINING A FUEL GAS INLETCHANNEL, A CONDUIT FROM SAID CHANNEL TO FURL GAS DELIVERY TUBE,ADJUSTABLE VALVE MEANS ASOCIATED THEREWITH FOR CONTROLLING FLOW OF THEGAS THERETHROUTH, A CONDUIT FROM SAID FUEL GAS INLET CHANNEL TO THE FUELGAS DELIVERY TUBE, QUICK-ACTING VALVE